package com.example.administrator.dialogdatepicker;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
import android.view.View;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
import android.widget.Button;
import android.widget.DatePicker;
import android.view.View.OnClickListener;
import android.app.DatePickerDialog;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private TextView showtime;
    private Button setdate;
    private int year;
    private int month;
    private int day;

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        showtime=(TextView) this.findViewById(R.id.showtime);
        setdate=(Button) this.findViewById(R.id.setdate);

        //初始化Calendar日历对象
        Calendar c=Calendar.getInstance(Locale.CHINA);

        year=c.get(Calendar.YEAR); //获取Calendar对象中的年
        month=c.get(Calendar.MONTH);//获取Calendar对象中的月
        day=c.get(Calendar.DAY_OF_MONTH);//获取这个月的第几天
        showtime.setText("当前日期:"+year+"-"+(month+1)+"-"+day); //显示当前的年月日

        //添加单击事件--设置日期
        setdate.setOnClickListener(new OnClickListener(){

            @Override
            public void onClick(View v)
            {
                //创建DatePickerDialog对象
                DatePickerDialog my_datePickerDialog=new DatePickerDialog(MainActivity.this,Datelistener,year,month,day);
                my_datePickerDialog.show();//显示DatePickerDialog组件
            }
        });

    }
    private DatePickerDialog.OnDateSetListener Datelistener=new DatePickerDialog.OnDateSetListener()
    {

        @Override
        public void onDateSet(DatePicker v, int y, int m,int d) {

            Date date = new Date();
            Date current_date = new Date();
            current_date.setYear(y - 1900);
            current_date.setMonth(m);
            current_date.setDate(d);

            if (date.getTime() >= current_date.getTime()) {

                //修改year、month、day的变量值，以便以后单击按钮时，DatePickerDialog上显示上一次修改后的值
                year = y;
                month = m;
                day = d;
                //更新日期
                updateDate();
            }
            else {
                Toast.makeText(MainActivity.this, "选择的日期不能大于初始日期，请重新设置", Toast.LENGTH_SHORT).show();

            }

        }
        //当DatePickerDialog关闭时，更新日期显示
        private void updateDate()
        {
            //在TextView上显示日期
            showtime.setText("当前日期："+year+"-"+(month+1)+"-"+day);
        }
    };
}
